Bellucci L G, Frignani M, Cochran J K, Albertazzi S, Zaggia L, Cecconi G, Hopkins H
Istituto di Scienze Marine - Sede di Bologna - Geologia Marina, Consiglio Nazionale delle Ricerche,Via P. Gobetti 101, 40129 Bologna, Italy.
J Environ Radioact. 2007;97(2-3):85-102. doi: 10.1016/j.jenvrad.2007.03.005. Epub 2007 May 2.
Five salt marsh sediment cores from different parts of the Venice Lagoon were studied to determine their depositional history and its relationship with the environmental changes occurred during the past approximately 100 years. X-radiographs of the cores show no disturbance related to particle mixing. Accretion rates were calculated using a constant flux model applied to excess (210)Pb distributions in the cores. The record of (137)Cs fluxes to the sites, determined from (137)Cs profiles and the (210)Pb chronologies, shows inputs from the global fallout of (137)Cs in the late 1950s to early 1960s and the Chernobyl accident in 1986. Average accretion rates in the cores are comparable to the long-term average rate of mean sea level rise in the Venice Lagoon ( approximately 0.25 cm y(-1)) except for a core collected in a marsh presumably affected by inputs from the Dese River. Short-term variations in accretion rate are correlated with the cumulative frequency of flooding, as determined by records of Acqua Alta, in four of the five cores, suggesting that variations in the phenomena causing flooding (such as wind patterns, storm frequency and NAO) are short-term driving forces for variations in marsh accretion rate.
对来自威尼斯泻湖不同区域的五个盐沼沉积物岩芯进行了研究，以确定它们的沉积历史及其与过去约100年期间发生的环境变化的关系。岩芯的X射线照片显示没有与颗粒混合相关的扰动。利用应用于岩芯中过量（210）Pb分布的恒定通量模型计算了堆积速率。根据（137）Cs剖面和（210）Pb年代学确定的各地点（137）Cs通量记录，显示了20世纪50年代末至60年代初全球（137）Cs沉降以及1986年切尔诺贝利事故的输入。除了在一个可能受德塞河输入影响的沼泽中采集的一个岩芯外，岩芯中的平均堆积速率与威尼斯泻湖平均海平面上升的长期平均速率（约0.25厘米/年）相当。在五个岩芯中的四个中，堆积速率的短期变化与由高潮记录确定的洪水累积频率相关，这表明导致洪水的现象（如风型、风暴频率和北大西洋涛动）的变化是盐沼堆积速率变化的短期驱动力。
